I wont a breeding pen set up to get the most color variation in the eggs.

Here's my idea:
Taking a large pen an an putting in 10 EE hens, 3 brown leghorn hens an 3 maran hens. Then add one roo of each. I think it would need a lot of stuff in the pen so the roos cant keep a watch on each other.

Hatching all the eggs from that pen should give me hens that lay dang near every color egg?

Some years ago, back in UK, a clever chap, by the came up with a good marketing plan. I thin I've got this right when I say, he got Cream Legbar cockerels (blue egg layers) & put them onto white egg, tinted egg, brown egg & dark egg laying breed hens. Then,if I remember correctly, put cockerels from these crosses onto the same colour egg layers. The results were very pretty; there were eggs of all manner of colours from blue right through to plum colour. He got some very smart looking egg boxes (navy blue & silver if my memory serves) & wrote some nice, cleverly worded, blurb about their being descended from some birds from ancient Patagonia (araucans?). They called their product "Old Cotswold Legbar Eggs". These eggs were very exceedingly popular in the supermrkets for a while, & sold for two or three times the price of other more familiar chicken's eggs.

We were inundated with telephone calls with people wanting to buy "Old Cotswold Legbars".

Gotta love the idea of making more proffit off of mutt eggs than purebreds. I am guilty of wanting to try this myself. My ee roo is always after the california grey hens and I have their eggs in the bator. Maybe in six months I'll be able to tell you what color eggs I get from the new girls. I think this is more of a flock management concideration...you have to look at the long term goals you have for your opperation. But keep in mind that the common standard breeds were developed over many generations for some sort of superiority, egg size, temperment, climate, longevity, quantity of eggs, and yes, color. In order to get a greater variety of color you could be breeding your flock to less productivity or other undesirable traits.
But isn't it fun!